<div>
<img src="{$smarty.const.BASE_URL_UPL}banners/{$banArq}" alt="" style="max-width:300px;"/>
</div>

<form action="{$smarty.const.BASE_URL_ADM}banners/editaimagemdb" method="post" enctype="multipart/form-data">
Enviar o arquivo: <input type="file" name="banArq" size="20"><br>
<input type="submit" value="Enviar">
<input type="hidden" id="banCod" name="banCod" value="{$banCod}" />
</form>